Delicious Bookmark this on Delicious Share on Facebook SlashdotSlashdot It! Digg! Digg



PHP : Function Reference : Image Functions : imagefontheight

imagefontheight

Get font height (PHP 4, PHP 5)
int imagefontheight ( int font )

Returns the pixel height of a character in the specified font.

Parameters

font

Can be 1, 2, 3, 4, 5 for built-in fonts in latin2 encoding (where higher numbers corresponding to larger fonts) or any of your own font identifiers registered with imageloadfont().

Return Values

Returns the height of the pixel.

Related Examples ( Source code ) » imagefontheight



Code Examples / Notes » imagefontheight

dev

This library function is very useful for variable-sized images that only contain text, like this function that I use to output error messages that accumulate and cause a fatal error in my thumbnailer:
<?php
function errimg($error) {
  // $error is an array of error messages, each taking up one line
  // initialization
  $font_size = 2;
  $text_width = imagefontwidth($font_size);
  $text_height = imagefontheight($font_size);
  $width = 0;
  // the height of the image will be the number of items in $error
  $height = count($error);
  // this gets the length of the longest string, in characters to determine
  // the width of the output image
  for($x = 0; $x < count($error); $x++) {
     if(strlen($error[$x]) > $width) {
        $width = strlen($error[$x]);
     }
  }
 
  // next we turn the height and width into pixel values
  $width = $width * $text_width;
  $height = $height * $text_height;
 
  // create image with dimensions to fit text, plus two extra rows and
  // two extra columns for border
  $im = imagecreatetruecolor($width + ( 2 * $text_width ),
                             $height + ( 2 * $text_height ) );
  if($im) {
     // image creation success
     $text_color = imagecolorallocate($im, 233, 14, 91);
     // this loop outputs the error message to the image
     for($x = 0; $x < count($error); $x++) {
        // imagestring(image, font, x, y, msg, color);
        imagestring($im, $font_size, $text_width,
                    $text_height + $x * $text_height, $error[$x],
                    $text_color);
     }
     // now, render your image using your favorite image* function
     // (imagejpeg, for instance)
     out($im, array(), $error);
  } else {
     // image creation failed, so just dump the array along with extra error
     $error[] = "Is GD Installed?";
     die(var_dump($error));
  }
}
?>
The function expects an array of error messages to be passed in, and then outputs an image containing the contents of the array.  This is especially useful if your code is contained in an html page that will display rexes if the images do not render correctly.
This function displays the array in image form with index 0 at the top, and the highest index at the bottom.
You have to write out() yourself though, see imagejpeg, imagepng, etc for good ideas on how to write a decent output function.


Change Language


Follow Navioo On Twitter
gd_info
getimagesize
image_type_to_extension
image_type_to_mime_type
image2wbmp
imagealphablending
imageantialias
imagearc
imagechar
imagecharup
imagecolorallocate
imagecolorallocatealpha
imagecolorat
imagecolorclosest
imagecolorclosestalpha
imagecolorclosesthwb
imagecolordeallocate
imagecolorexact
imagecolorexactalpha
imagecolormatch
imagecolorresolve
imagecolorresolvealpha
imagecolorset
imagecolorsforindex
imagecolorstotal
imagecolortransparent
imageconvolution
imagecopy
imagecopymerge
imagecopymergegray
imagecopyresampled
imagecopyresized
imagecreate
imagecreatefromgd2
imagecreatefromgd2part
imagecreatefromgd
imagecreatefromgif
imagecreatefromjpeg
imagecreatefrompng
imagecreatefromstring
imagecreatefromwbmp
imagecreatefromxbm
imagecreatefromxpm
imagecreatetruecolor
imagedashedline
imagedestroy
imageellipse
imagefill
imagefilledarc
imagefilledellipse
imagefilledpolygon
imagefilledrectangle
imagefilltoborder
imagefilter
imagefontheight
imagefontwidth
imageftbbox
imagefttext
imagegammacorrect
imagegd2
imagegd
imagegif
imagegrabscreen
imagegrabwindow
imageinterlace
imageistruecolor
imagejpeg
imagelayereffect
imageline
imageloadfont
imagepalettecopy
imagepng
imagepolygon
imagepsbbox
imagepsencodefont
imagepsextendfont
imagepsfreefont
imagepsloadfont
imagepsslantfont
imagepstext
imagerectangle
imagerotate
imagesavealpha
imagesetbrush
imagesetpixel
imagesetstyle
imagesetthickness
imagesettile
imagestring
imagestringup
imagesx
imagesy
imagetruecolortopalette
imagettfbbox
imagettftext
imagetypes
imagewbmp
imagexbm
iptcembed
iptcparse
jpeg2wbmp
png2wbmp
eXTReMe Tracker